Submission #932417

#	Time	Username	Problem	Language	Result	Execution time	Memory
932417		pan	Dreaming (IOI13_dreaming)	C++17	100 / 100	70 ms	19256 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//#include "bits_stdc++.h"
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define lb lower_bound
#define ub upper_bound
#define input(x) scanf("%lld", &x);
#define input2(x, y) scanf("%lld%lld", &x, &y);
#define input3(x, y, z) scanf("%lld%lld%lld", &x, &y, &z);
#define input4(x, y, z, a) scanf("%lld%lld%lld%lld", &x, &y, &z, &a);
#define print(x, y) printf("%lld%c", x, y);
#define show(x) cerr << #x << " is " << x << endl;
#define show2(x,y) cerr << #x << " is " << x << " " << #y << " is " << y << endl;
#define show3(x,y,z) cerr << #x << " is " << x << " " << #y << " is " << y << " " << #z << " is " << z << endl;
#define discretize(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());
using namespace std;
//using namespace __gnu_pbds;
//#define ordered_set tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
//#define ordered_multiset tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
typedef long long ll;
typedef long double ld;
typedef pair<ld, ll> pd;
typedef pair<string, ll> psl;
typedef pair<ll, ll> pi;
typedef pair<ll, pi> pii;
ll n, m, l, counter = 0, farest, dis, dia = 0;
ll const INF = 1e13;
vector<ll> radii;
vector<pi> adj[100005];
bool joined[100005];
vector<ll> cc;
vector<ll> dist1(100005, INF);
vector<ll> dist2(100005, INF);
void dfs(ll p, ll from, vector<ll>& dist)
{
	if (!joined[from])
	{
		cc.pb(from);
	}
	joined[from] = true;
	for (pi u: adj[from])
	{
		if (p==u.f) continue;
		dist[u.f] = dist[from] + u.s;
		if (dist[u.f]>dis) {dis= dist[u.f], farest = u.f;}
		dfs(from, u.f, dist);
	}
	
}

int travelTime(int N, int M, int L, int A[], int B[], int T[])
{
	n = N, m = M, l = L;
	for (ll i=0; i<m; ++i)
	{
		adj[A[i]].pb(mp(B[i], T[i]));
		adj[B[i]].pb(mp(A[i], T[i]));
	}
	for (ll i=0; i<n; ++i)
	{
		if (joined[i]) continue;
		counter++;
		cc.clear();
		dist1[i] = 0;
		farest = i;
		dis= 0 ;
		dfs(-1, i, dist1);
		
		ll first = farest;
		dist1[first] = 0;
		dis=0;
		farest = first;
		dfs(-1, first, dist1);
		ll second = farest;
		dia = max(dia, dis);
		
		dist2[second] = 0;
		dfs(-1, second, dist2);
		ll radius = INF;
		for (ll j=0; j<ll(cc.size()); ++j)
		{
			radius = min(radius, max(dist1[cc[j]], dist2[cc[j]]));
		}
		radii.pb(radius);
	}
	if (n==1) return 0;
	if (n==2) return (m==1)?dia:l;
	sort(radii.begin(), radii.end(), greater<ll>());
	ll ans = dia;
	if (counter>1) ans = max(ans, radii[0] + radii[1]+ l);
	if (counter>2) ans = max(ans, radii[1] + radii[2]+ 2*l);
	return ans;
	return 0;
}
 

• Subtask 1: 14 / 14
• Subtask 2: 10 / 10
• Subtask 3: 23 / 23
• Subtask 4: 18 / 18
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23